Vapor generator



Aug 4, 1953 w. T. MOORE VAPOR GENERATOR Aug. 4, 1953 Filed June 2, 1949000000000000 A00 OOOOOOOOODOgg OOOO W. T. MOORE VAPOR GENERATOR 2sheets-sheet 2 SO o oor

G OOOOWQOCOOOOOG 00 OO O0 004700000000000@ FIGS Patented Aug. 4, 1953VAPOR GENERATOR William T. Moore, Elmhurst, Ill., assignor to TheBabcock & Wilcox Company, New York, N. Y., a corporation of New JerseyApplication June 2, 1949, Serial No. 96,731

Claims.

This invention relates to fluid heat exchange apparatus in Which a vaporgenerator such as a water-tube type of steam generator is utilized toabsorb heat from a gaseous medium at a high temperature (i. e.,200G-2600" F.) and under substantial pressure (i. e., 250-350 p. s. i.)

The invention involves an exterior pressure vessel of sufficiently largedimensions (i. e., height 50-100 feet, diameter 10-20A feet) to housethe gas generator or furnace component and the tubular pressure partcomponents of a vapor (or elastic fluid such as steam) generator withprovisions for the necessary circulation of the internal and externalheat exchange fluids involved.

As an example of the use of the invention, it may be employed inchemical processes in which the exterior pressure vessel constitutes ashell through which gaseous reactants or reactance products pass attemperatures of the order of 2500 F. and pressures of the order of 300p. s. i. For example, oxygen, natural gas, or methane may be supplied tothe shell as reactants, and the high temperature products of theirreaction are then passed overl the heat exchange parts of a vaporgenerator. The vapor or steam generator is employed, in such a process,to control the temperature of the gaseous products. In some processes itis important that the gaseous reactance products be reduced from atemperature of the order of 2500 F. to a temperature of the order of600? F. This illustrates Ione of the results accomplished by theinvention, and the -overall process more effective. By this arrangement,provisions which must be made for differential movements of the pressureparts and .the shell are minimized, and there is less pressure drop inthe gases passing through the shell. The vapor generating system withinthe shell involves a bank of upright tubes having their upper `endsrigidly connected to a liquid and vapor drum and their lower ends t0 aliquid drum, the bank of `tubes and drum arrangement constituting anassembly which is supported by the shell at a position adjacent theupper drum.

' In a preferred embodiment of the invention,

ythe vapor or steam produced is conducted from 2 the upper part of theupper drum to a radiant superheater which includes a circular series ofupright tubes arranged around the interior surface of the shell andfunctioning as shell wall cooling tubes to protect the shell againstoverheating.

In one process in Which the invention is employed, natural gas is burnedwith a .deciency of oxygen in a combustion chamber (or reaction chamber)disposed in the shell but below the vapor generator. These gases reactto develop gaseous products which pass upwardly from the combustionchamber and are caused to recurrently pass back and forth transverselyof the bank or banks of vapor generating tubes before they leave theshell at its upper part. The natural gas and the oxygen react underpressures of the order of 300 p. s. i. and are effective in creatinggaseous products within the temperature range of 20002500 F.

The apparatus of the invention is illustrated by an embodiment which isdisclosed in the accompanying drawings in which:

Fig. 1 is a vertical section on the line I-l of Fig. 4;

Fig. 2 is a multiple plane vertical section on the section line 2-2 ofFig. 4;

Fig. 3 is a horizontal section on the line 3-3 of Fig. 1;

Fig. 4 is a horizontal section on the line 4-4 of Fig. 1;

Fig. 5 is a fragmentary View of Fig. 4 on an enlarged scale;

Fig. 6 is a view in the nature of a vertical section on the line 6--6 ofFig. 3, particularly showing the manner in which the upper drum of thevapor generator is supported within the shell;

Fig. 7 is a partial elevation showing two adjoining superheater tubesand the manner in which they are secured to the shell;

Fig. 8 is a partial horizontal section on line 8-8 of Fig. 7;

Fig. 9 is a 'partial horizontal section on the line 9 9 of Fig. 1,showing a full stud tube construction employed in a furnace zone ofhightemperature; and

Fig. l0 is a partial horizontal section on a line l U-lll of Fig. 1,showing a partial stud tube wall construction for a reaction zone oflower temperature.

The shell I0 is a Welded steel pressure vessel which may have a diameterof from l0 to 20 feet and a height o f 50 to 100 feet. It is fabricatedto withstand internal fluid p-ressures considerably in excess of 300 p.s. i., and it is provided with gas inlets at its lower portion and a gasoutlet such as l2 at its upper part.

Within the lower part of the shell IIJ is a combustion chamber orreaction chamber, ld with thick refractory walls through which there aregas inlet ports such as l and I8, these ports also extending through theshell l as indicated in Fig. 1. :In its upper part, the combustionchamber is provided with outlet ports such as 29 and 22, acting as apart of means directing high temperature gases over the heat exchangeparts of the vapor generator.

The vapor or steam generator within the shell lil includes a transverseupper drum 2*!5 connected by banks 26 and 2E of steam generating tubesto a lower drum 3G. The tubes are expanded into tube seats in the drumsin a manner well-.known in the art to form pressure tight connections,vand the entire unit is suspended within the shell `by means includingan arrangement oi elements such 'as that particularly indicated vin Fig.'6. This arrangement involves a roller 'supporting bracket 32 secured'to the wal-l of the shell ill, and an upper bracket 3d secured to thedrum 24. and resting upon 'a roller et, which, in turn, is supported bythe bracket 32. There is a similar arrangement of drum supportingelements at 'each vside ci the shell, as indicated in Fig. 2.

The banks of `vapor 'generating tubes 26 yand 28 are separated by a'diametrically disposed wall i Sl ('see Fig. ll) 'which `in'ciudes thelarge diameter upright d'own'corn'er tubes 'su'ch Aas fr0- 428. Thespaces between these downcomer 'tubes 'are closed "by means shown 'asrefractory 'material to ycomplete the Wallin the iorm indicated in Fig.4. These downcomers, being 'straight 'tubes yand of greater structural'strength than the smaller diameter 'tubes of the banks 2t Aand 2S,provide Aa 'major part of the support necessary for the lower drum 30.One of the down'comer tubes, the tube 11E, 'has a blow-'down ltube 50extending Vtherethrough Afrom the 'lower part or the lower drum 3B to aposition within the upper drum, indicated at '52 'in Fig. 2. From thisposition, the vblowndown tube extends laterally through the'clruln 'andshell 'walls to a blow-down valve (not .shown).. The lateral extensionof the blow-d0wn tube is 'indicated at 5l '(Fi'g. '3) Itis provided'withthermal sleeve constructions 53 and .5d similar to that indicated 'at'li'l -for -the 'feed water connection Il'l. rhe latter act as a `partof means for 'supplying 'the vapor generator Awith a liquid forcirculation therethrough. Tubular connections 'lll and T39 for a gaugeglass '6l have similar thermal 'sleeve constructions Vt3 and '65.

The lower part of 'the lower drum '3'0 is protected from the highertemperature gases Yadjacent the combustion chamber 'i4 by a refractory'covering '5d which may 'be Jheld Vin position on the lower Vpart oflthe drum wall by metallic- 'projections Ywelded to Athe drum. l'Thiscovering also extends over a manway opening 556 which is normally closedby ya plate B attached to 'the drum by appropriate or suitable holdingmeans.

IBelow drum cover 51.5 'is a refractory vbody '60 for increasing thethermalprotection of the lower part of the drum 30.

The gaseous reaction products from 'the com- -bustion vchamber It pass'through the outlets 20 i horizontally ,extending 'baffles "I0-Jil. Thebaffles "EG, l2, 1d, l5, 71, T9 extend radially inwardly from the shellto a position adjacent the inner rows or" tubes of the associated banksof tubes 26 and 28, and the remaining baffles extend from the wall 36outwardly on both sides thereof to the outermost rows of the banks oftubes. The baiiles constitute means directing high temperature gasesover the banks of tubes connecting the drum 24 with the drum 3G.

A vapor, or steam under pressure, passes from the upper part of the drum26 to the circular inlet header of the superheater. This header may beformed by a number of arcuate sections such as '8i- Ell which areindividually supplied with steam 'from the drum 2d by the tubularconnections such as '9i-94 (Fig. 3). These connections `and the headerconstitute means connecting the superheater with the drum 24. Extendingdownwardly frorn each of the sections of the upper superheater header803, are wall tubes such as the tubes 'd6-98. r'Zlhese tubes are held'in position in substantial contact with the Wall ci the shell Ylll bymeans such as that indicated in YFigs. '7 and 18. This means includes ametallic sleeve it@ welded to the shell as indicated at H12. Slidablyextending into the upper end of 'the sleeve itil is the downwardlyextending portion let of a right angle bent rod. The 'upper portion l'd-of this rod is welded to the tube @i5 -as indicated at ldd. Asinrila-rrod H18 is secured to the tube t8 and 'has its upwardly extendingportion disposed within the llower part of the sleeve ll. it is to ybeunderstood that such securing Adevices are distributed throughout the"length land width 'ci the wallfof ysuperhe'ater tubes which constitutesa lining for the 'shell l0.

In the higher temperature 'gas Zones, and prefcrab-ly up to the level ofthe A:baliies 'i2 and 71, Ythe superheater tubes 'are fully studded, asindicated in Fig. '9. 'The faces 'of these tubes toward the linterioro'i the shell, aswell as the 'side faces 'of the tubes, have welded'thereon 'studs 'such las those indicated 'at H )-'11ll, 'and the 'shell:lining is 'completed "by a refractory material :stratum `such as it@packed around the tubes and studs in a semi-'plastic condition, las iswell-"known in the art. In a lower 'temperature 'zone the superheatertubes 'such vas 9E and '98 'are only partially studded, the races of thetubes ysuch as and '22 presented Mtoward the interior "of the shell arenot 'covered with the studs :and refractory construction. 'The lowerparts "of some of Vthe superheater tubes Aare Vbent 'around the gasports t6 'and 'la `oi the combustion chamber, and all of `thesuperheater tubes extend below 'these ports 'to a connection with alowersuperheater header 30. Superhea'ted steam passes 'from the .circularheader IS to an outlet header T32 which extends through an yopening T315lin the base or support .itt .for the shell lll. Connections between theA.-lfieaders 430 and |3.2 Aare .indicated at lm-M3.

In order :that :saturated steam -or vapor may be `conducted zdirectly:from the dr-um to Aone or .more safety vvalves and to 'the superheater,drum Y215 has connected therewith a tubular -'outlet 150 which extendsthrough an opening fat the 'top of 'the .shell t0 :and 'lis v.connected'therewith 1byr-a pressure tight Lexpansion iointfconsitruction such asW2. fllfle'tubular'outlet |950, withorwithout the -tubes 495| and Ithesuperheater zand its connections, constitutes means connected with theva-por generating tribes and extending through :the shell Ill toconstitute Ioutlet 'for-vapor unlll"der pressure. T'The' tubular outletlalso constitutes -a safety valve conduit.' To provide 'for' access tothe interior of the drum 24, there is ay manway construction |60 securedto the drum and aligned with another `manway construction |62 4which issecured to the shell l at the position indicated in Fig. 2.

constitutes a feed pipe connection extend- I ing through the shell at|12 and connected with the drum at |14-as means for the purpose ofsupplying the vapor generator with a liquid from which the vapor is tobe generated.

y From the above description, it .will be noted that the shell of the vpressure .vessel acts as a column in which the steam ,generator issupported. The load of the pressure vessel and the steam generator isvtaken at the base of the installation upon support |36. lThis supportmay be convenientlyl shaped, as.V 1a. cylinder which is in directcompression.

The superheater wall tubes 98 are supported in idirect compression fromthe header |30, this header being supported by theA shell I0, as by4inwardly extending brackets |80 similar to the upper brackets 32,secured to the shell. With this permitted* without undesirable stress,by reason ,i

'of the looped construction of the superheater supplyl tubes such asSIL-94.

The support of the steam generator at a position near the brackets 34permits the tubular "feed water connections, and other connections suchas the gauge glass conduits 51 and 59. to be brought out of the pressurevessel at a'level coincident with the transverse axis of the upper drum24. With this arrangement, there will ber very slight relative movementbetween such connections and the shell of the pressure vessel. Whatlittle movement thereby will be readily taken up by the bent or loopedconstruction of these connections.

While in accordance with the provisions of the statutes I haveillustrated and described herein the best form of my invention now knownto me, those skilled in the art will understand that changes may be madein the form of the apparatus disclosed without departing from the spiritf of the invention covered by my claims, and that certain features of myinvention may sometimes be used to advantage Without a corresponding useof other features.

What is claimed is:

1. In fluid heat exchange apparatus, a metallic pressure vesselconsisting of an upright cylindrical shell of large volume, a vaporgenerator including upper and lower drums and connecting banks of vaporgenerating tubes disposed as a unit within the shell and pendentlysupported from the upper part of the shell, a row of large diameterdowncomer tubes disposed between said banks of tubes and directlyconnecting said upper and lower drums, a high pressure combustionVchamber within the shell, baiiles directing high temperature gases fromthe combustion chamber over said banks of tubes and to a gas outlet atthe opposite part of the shell, tubular means through which the vaporgenerator is supplied with a liquid for circulation therethrough and thedevelopment of a vapor under pressure, a superheater including a row ofclosely spaced tubes disposed closely adjacent to and distributed incircular arrangement around the inner vof 'vaporvgenerating rtubesdisposed as a unit ysurface of Athe shell, loopedtubular meansconnecting the vapor space of the upper drum with the upper ends of thesuperheater tubes, and a superheater outlet header secured to the shelland connected with the lower ends of the superheater tubes.

y A"2. In fluid heat exchange apparatus, a metallic pressure vesselforming an upright cylindrical shell of large volume, a vapor generatorincluding upper and lower drums and connecting banks within the shelland pendently supported thereby, a row otspaced large diameterdowncomers directly connecting said upper and lower drums, refractorymeansA associated with the downcomer tubes to ll the spaces between themand complete a wallv extending across the shell and separating the banksof tubes, means directing high' temperature gases from one part of theshell over said banks of tubes and to a gas outlet at the opposite partof the shell, tubular means through which the vapor generator issuppliedwith a liquid for circulation therethrough and the development of avapor under pressure, a superheater including a row of closely spacedtubes disposed closely adjacentto and distributed in 'circulararrangementl around the inner surface of the shell, looped tubular meansconnecting the vapor space of the up-per drum with the upper ends of thesuperheater tubes, and a header constituting a superheater outletconnected with the lower ends of the superheater tubes, said headerbeing secured to the lower part of the pressure =vessel to form a bottomsupport for the superheater.

3. In fluid heat exchange apparatus, a large diameter metallic pressurevessel adapted for the passage yof high temperature and high pressuregases therethrough in normal operation, a heat absorbing unit heated bysaid high pressure gases including tubes vertically disposed within thepressure vessel, supporting means near the top of the pressure vesselfor pendently supporting said heat absorbing unit, upper and lower drumsincluded in said heat absorbing unit, the supporting means beingconnected to the upper drum, a feed water connection to the upper drum,a blow-down tubular connection extending from the lower drum and thenthrough the upper drum and the wall of the pressure vessel to theatmosphere in the horizontal zone of said supporting means, a bottomsupported superheater including upper and lower ring headers and a ringof upright wall tubes adjacent the wall of the pressure vessel, a safetyvalve conduit extending upwardly from the upper drum through the Wall ofthe pressure vessel, looped superheater supply tubes in communicationwith the safety valve conduit and the upper header of the superheater tosupply steam to the latter, and tubular means extending from the lowerheader of the superheater through the wall of the pressure vessel forthe delivery of superheated steam.

4. In fluid heat exchange apparatus, a large diameter metallic pressurevessel providing an upright cylindrical shell adapted for the passage ofhigh temperature and high pressure gases therethrough in normaloperation, a heat absorbing unit heated by said high pressure gasesincluding tubes vertically disposed within the pressure vessel,supporting means near the top of the pressure vessel for pendentlysupporting said heat absorbing unit, upper and lower headers or drumsincluded in said heat absorbing '7 unit, a fvaporrzaele liquidoomieotron 4.to upper dromer header, .1a :blow-'down tubular foon-Ymention extendtng :from the lower drum and then through the lupperdrum'or 'header :and through 1the1x1/refiler the pressure vessel to theatmosphere in the horizontal zone of said supporting means, a h'ottomsupported superheater inoludingupper ,and lower ring headers and arngofupright wall tubes adjacent the wall of the pressure vessel,

:a :safety valve conduit extending ,from .the upper ,I

drum or .header fof said unit :through the wall of 'the 'pressure vesselin :said :horizontal zone, lbowed :superheater Asteeply tubes -directlyvconnecting the .safety valve oon'duitand'the upper header lof .the

superheater, .and tubular .means extending from Y l the .ll'ower .headerof the superheater through the Wall of the pressure vessel .for thedelivery of superheated ria-por.

f5. n =ilu-icl `heat 4exchange apparatus, an upright nylindriealpressure vessel formi-ng va shell of arge volume, a ring of .uprightHuid conduct- Wa'll leovzrlng tubes lcont-iguously 4arranged re1- atve.to the 'inner :surface fof the shell and vextending Vfrom a ,positionnear the bottom Vof the shell to a position .near its top, :a thick'Walled refractory construction .presenting a .high 'temperaturereaction `chamber within said ring of .tubes and disposed vat fthe lowerpart .of the shell, 4the upper part 'of the treaction chamber havingopenings xfor ithe upward exit yof high temperature :gaseous .reactionproducts, separated groups of horizontal-ly spaced upright vaporgenerating vtubes -disposed Within the shell above the reaction chamber,pressure parts .constituting upper and lower Huid Chambers which areconnected rb'y the vapor generating tubes, means other than vsaid sap/orgenerating 'ltubes connecting said 'upper 'and lower xvoh'arnioers,ioafe means causing `the reaction 'products to pass over the groups of'tubes in a plurality fof transverse gas passes,

8 means 'romaine fan yexit passage for the .reaction products near thetop 4of the shell, .refractory baffle Ameans associated with thedowncorners Aand separating groups fof tubes. means foormeet- :ing ftherling of tubes to the :Huid l-systen'r of vthe 7vapor .generatingitubes, said `last named means including header means and .bent tubularconnections eommurucating `'with the upper header :lower hea-der means.at fthe .lower ends `of `said 'ring #of 'tubes and connected thereto,means yseoured to the shell for affording Abottom support for the lower.header means and sad ming `of tubes, and means `'secured to the upperzpant fof vthe .shell for pendentiy supporting .the groups of vaporgenerating tubes. i

T. MOORE.

.References -Cited in the Sle of `this -pastent STATES .Number Name"Date 91,294 Wilfong June 15, 1869 1,068,301 Bettington July 22, T91321,270,621 Kestner June .25, 1'918 `175I343 Steinmuller VMay G, 19301,789,427 Belling e't Pa1. Jan. "20, 1'931 1,846,428 Kunz Feb. y23, 19321,881,275 Huff Oct. 4, v1932 l1,903,521 Taggart Apr. l1, 1933 1,9%,939Noaok Feb. A2'?, 1934 i2,007,540 LaMontI July 9 '19.35 2,037,493'Biersak 'et z9l1.. .llll1;)1. 14, 1936 .2,055,362 Peters Sept. 22, 19362,124,215 Stillman July '19, 1938 2,313,061 Frisch 'Mar v9, 1943'2,383,634 Alexandrou Aug.'2l, 1'945 2,594,330 lllayhew Apr. '29 1952.FOREIGN PATEN 'Number A"Country Date 12,004 'Greait'ritain Nov. '14,41912

